Graphite films are used as heat-radiating components for semiconductor elements or other heat-generating components provided in a variety of electronics and electric devices such as computers. A graphite film having an excellent mechanical strength and flexibility as shown in FIG. 1 is obtained as follows (Patent Literature 1). A polymer film having a thickness of 75 μm is heated up to a temperature of 1,000° C. in a nitrogen gas so as to obtain a carbonized film. The carbonized film thus obtained is heated up to 3,000° C. in an argon atmosphere so as to obtain a graphitized film. The graphitized film thus obtained is subjected to a rolling treatment, thereby obtaining the graphite film.